I think using a simple single threaded executor gets you little context switching and such. The issue is that async generator codegen currently is not as good

I think using a simple single threaded executor gets you little context switching and such. The issue is that async generator codegen currently is not as good as we want it to be. Async futures currently take more space than they need to and have some issues with drop tracking. They're sound, but not necessarily efficient. These are not problems with the language or the feature, just the current implementation